To be sure, you should:
* Consult your owner's manual: This is the best resource for the exact location on your specific vehicle.
* Use a repair manual: A Haynes or Chilton manual for your year and model will have diagrams showing the EGR valve location.
* Search online: Searching for "2001 Chevy Impala [engine size] EGR valve location" with images will show pictures that may help you identify it.
Remember that working on your vehicle's emission system can be complex. If you're not comfortable performing the work yourself, it's best to take your car to a qualified mechanic.